A DSR is a signaling Network Element (NE) composed of OAM servers and Message Processors, and can include the Diameter Intelligence Hub.
The DSR can be deployed either as a core router that routes traffic between Diameter elements in the home network, or as a gateway router that routes traffic between Diameter elements in the visited network and the home network. The DSR serves primarily as a Diameter Relay Agent to route Diameter traffic based on configured routing data.
DSR Network Elements (NEs) are deployed in geographically diverse mated pairs with each NE servicing signaling traffic to and from a collection of Diameter clients, servers, and agents. One DSR Diameter Agent Message Processor (DA-MP) provides the Diameter message handling function and each DA-MP supports connections to all Diameter Peers (defined as an element to which the DSR has a direct transport connection).
- Network configuration, including servers, server groups, and message processors.
- Diameter protocol configuration, including configuration for routing functions and configuration for transport connection management
- Configuration of activated DSR Applications
In the DSR topology, the OAM server function is split into Network OAM (NOAM) servers and System OAM (SOAM) servers. A DSR with a pair of NOAM servers is connected to multiple DSRs in the network. A single NOAM will support up to 32 signaling servers. Each DA-MP resides with a pair of SOAM servers that interact directly with the respective DA-MPs on that DSR.
- Each DSR service signals traffic to and from a collection of Diameter clients, servers, and agents.
- Each DSR supports :
- OAM servers (OAM), operating in Active/Standby mode; NOAM and SOAM servers.
- Two message processors (DA-MPs), operating in Active/Standby or Active/Active mode.
- The DSR MPs provide the Diameter message handling function. Each DSR MP supports connections to all of the DSR Peers.
- DSRs are deployed in mated pairs for purposes of geo-redundancy.
- The Integrated Diameter Intelligence Hub (IDIH) provides the ability to filter, access, and troubleshoot Diameter transactions,
DSR Topology
In DSR topology, as shown in Figure 1, there are NOAM servers, SOAM servers, and MP servers.
- On a DSR NOAM, network topology data (such as user accounts, network elements, servers, and server groups). Network-wide Policy and Charging(PCA) data, MAP-Diameter Interworking data for MD-IWF and Diameter Topology Hiding data are configured on NOAM GUI pages. Diameter Common provides the Import and Export GUIs on the NOAM for exporting and importing the SOAM configuration data for Diameter Configuration, IPFE, and DSR Applications.
- On a DSR SOAM, Diameter signaling data (such as Local Nodes, Peer Nodes, Peer Node Groups, Connections, Route Groups, and Route Lists), Diameter MAP Interworking data for DM-IWF, DSR Application data (RBAR, FABR, CPA, Policy and Charging (PCA), and GLA), Profile Assignments and IPFE configuration data. Diameter Common provides the Import and Export GUIs on the SOAM for exporting and importing the SOAM configuration data for Diameter Configuration, IPFE, and DSR Applications.
The DA-MP servers process the database updates from NOAM servers and SOAM servers and perform the real-time signaling. The DA-MP servers also supply the Platform Measurements, Events, Alarms and Logs (MEAL) data, Diameter signaling MEAL data, and DSR Application MEAL data to SOAM servers. The SOAM servers retain the Diameter signaling MEAL data and DSR Application MEAL data, and merge the Platform MEAL data to the NOAM servers.
Deployment with SDS
DSR deployments that include support for the DSR Full Address Based Resolution (FABR) application must be deployed with the Subscriber Database Server (SDS). The SDS is used to provision the FABR subscriber data.
The SDS/DP system consists of a Primary Provisioning Site, a Disaster Recovery (DR) Provisioning Site, and up to 32 DSR Signaling Site servers with redundant DP SOAM servers. Each Provisioning Site has an Active/Standby pair of servers in a high availability (HA) configuration and a third server configured as a Query Server.
In DSR topology, the DSR SOAM and the SDS SOAMP servers are run on the DSR OAM blade using virtualization technology. It is assumed that most deployments that support both DSR and SDS will deploy the DSR NOAMP on Rack Mount Servers, as this is how the SDS NOAMP is deployed. Small deployments that minimize the amount of hardware investment require the DSR NOAMP to be deployed as a virtual server on the OAM blade. This requires running three Virtual Machines (VMs) on the blade – DSR NOAM, DSR SOAM and SDS SOAMP.
OAM Servers
A pair of Operation, Administration, and Maintenance (OAM) servers make up one OAM component of the DSR. This pair of servers has an Active/Standby relationship. The Active server in the pair controls the virtual IP addresses (VIP) that direct XMI and IMI traffic to the Active server.
The role of the OAM server is to provide a central operational interface and all OAM&P functions (for example, user administration, provisioning and configuration data, database administration, fault management and upgrade functions) for the DSR under its control. The OAM server replicates configuration and provisioning data to and collects all measurements, events, alarms, and log data from all Message Processors within the DSR.
- A central operational interface
- Distribution of provisioned data to all MPs of the NE
- Event collection and administration from all MPs
- User and access administration
- Support for a northbound SNMP interface toward an external EMS/NMS; up to 5 SNMP destinations can be configured
- A web-based GUI for configuration tasks
Figure 2 illustrates the DSR OAM architecture.
Message Processors
The role of the Message Processors (DA-MPs) is to provide the Diameter application messaging interfaces, message processing functions, and message routing functions to the DSR Applications that run on them. All Message Processors replicate configuration data from the OAM servers and send measurements, events, alarms, and log data to the OAM servers.
Integrated Diameter Intelligence Hub
The Integrated Diameter Intelligence Hub (IDIH) provides the ability to filter, access, and troubleshoot Diameter transactions without the need for separate probes or taps. See Integrated Diameter Intelligence Hub.